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Astroparticle Physics in Intergalactic Space Matteo Viel – INAF Trieste

Astroparticle Physics in Intergalactic Space Matteo Viel – INAF Trieste APP14 – Amsterdam, 24 th June 2014. OUTLINE . INTRO: the Intergalactic Medium and its main manifestation: the Lyman- a forest QUANTITATIVE CONSTRAINTS: neutrinos and warm dark matter

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Astroparticle Physics in Intergalactic Space Matteo Viel – INAF Trieste

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  1. Astroparticle Physics in Intergalactic Space MatteoViel – INAF Trieste APP14 – Amsterdam, 24th June 2014

  2. OUTLINE INTRO: the Intergalactic Medium and its main manifestation: the Lyman-a forest QUANTITATIVE CONSTRAINTS: neutrinos and warm dark matter TOOLS: beyond linear theory with N-body/hydrodynamic simulations DATA: state-of-the-art observables at high and low resolution (BOSS and UVES spectra)

  3. INTRO - why atomic physics is important for intergalactic space - baryons in intergalactic space are diffuse/low density - physics of the IGM is relatively simple (at least at large scales)

  4. The Lyman-a forest Lyman-a absorption is the main manifestation of the IGM Tiny neutral hydrogen fraction after reionization…. But large cross-section

  5. The Intergalactic Medium: Theory vs. Observations 80 % of the baryons at z=3 are in the Lyman-a forest Bi & Davidsen (1997), Rauch (1998) Review by Meiksin (2009) baryons as tracer of the dark matter density field dIGM~dDMat scales larger than the Jeans length ~ 1 com Mpc t ~ (dIGM)1.6 T -0.7

  6. Dark matter evolution: linear theory of density perturbation + Jeans length LJ ~ sqrt(T/r) + mildly non linear evolution Hydrodynamic processes: mainly gas cooling cooling by adiabatic expansion of the universe heating of gaseous structures (reionization) - photoionization by a uniform Ultraviolet Background - Hydrostatic equilibrium of gas clouds dynamical time = 1/sqrt(G r) ~ sound crossing time= size /gas sound speed Modelling the IGM: Physics Size of the cloud: > 100 kpc Temperature: ~ 104 K Mass in the cloud: ~ 109M Neutral hydrogen fraction: 10-5 In practice, since the process is mildly non linear you need numerical simulations To get convergence of the simulated flux at the percent level (observed)

  7. DATA vs THEORY

  8. P FLUX (k,z) = bias2 (k,z) x P MATTER (k,z) DATA vs THEORY

  9. DATA vs THEORY

  10. END OF INTRO We have characterized the physics of the IGM and we can now fully exploit the fact that: The IGM is a probe of matter fluctuations and geometry, a laboratory for fundamental physics, a sink (and a reservoir) for (of) galactic baryons

  11. SDSS- III/BOSS: Dynamics 1D Lyman-a flux power Palanque-Delabrouille et al. 2013

  12. SDSS-III/BOSS: Geometry New regime to be probed with Lyman-a forest in 3D Slosar et al. 11 Busca et al. 13 Slosar et al. 13

  13. SDSS- III 3D cross-correlation between Lyman-a flux and quasars Font-Ribera et al. 2013

  14. TO RECAP: WHY LYMAN-a? ONE DIMENSIONAL AND ALSO THREE DIMENSIONAL HIGH REDSHIFT e.g. Kaiser & Peacock 91 1D cross spectrum e.g. Viel et al. 02 Where you are possibly closer to primordial P(k) …unfortunately non-linearities and thermal state of the IGM are quite important….

  15. CONSTRAINTS ON COSMOLOGICAL NEUTRINOS

  16. COSMOLOGICAL NEUTRINOS - I: WHAT TO START FROM Lesgourgues & Pastor 06 COSMOLOGY constraints on the sum of the neutrino masses

  17. COSMOLOGICAL NEUTRINOS - II: FREE-STREAMING SCALE Neutrino thermal velocity Neutrino free-streaming scale Scale of non-relativistic transition RADIATION ERA z>3400 MATTER RADIATION z<3400 NON-RELATIVISTIC TRANSITION z ~ 500 THREE COSMIC EPOCHS Below knr there is suppression in power at scales that are cosmologically important

  18. COSMOLOGICAL NEUTRINOS - III: LINEAR MATTER POWER CMBGALAXIESIGM/WEAK LENSING/CLUSTERS Increasing neutrino mass Lesgourgues & Pastor 06

  19. MASSIVE NEUTRINOS

  20. COSMOLOGICAL NEUTRINOS : NON-LINEAR MATTER POWER Bird, Viel, Haehnelt (2012) 20% more suppression than in linear case, redshift and scale dependent. FEATURE!!! P massive / P massless LINEAR THEORY NON-LINEAR NAÏVE EXTENSION OF LINEAR THEORY Cosmic Scale http://www.sns.ias.edu/~spb/index.php?p=code

  21. CONSTRAINTS on NEUTRINO MASSES USING NON-LINEARITIES Xia, Granett, Viel, Bird, Guzzo+ 2012 JCAP, 06, 010 If using just linear 0.43eV – Improvement is about 20% when extending to non-linear

  22. NEUTRINOS IN THE IGM DATA SIMULATIONS CONSTRAINTS FROM IGM ONLY: Smn<0.9 eV(2s) Viel, Haehnelt, Springel 2010

  23. CONSTRAINTS on NEUTRINO MASSES FROM Planck: I Smn<0.93 eV(2s) Costanzi+ 2014

  24. CONSTRAINTS on NEUTRINO MASSES FROM Planck+BAO: II Smn<0.24 eV(2s) Costanzi+ 2014

  25. CONSTRAINTS on NEUTRINO MASSES FROM Planck+BAO+oldLya: III Smn<0.14 eV(2s) Costanzi+ 2014

  26. THE COLDNESS OF COLD DARK MATTER Viel, Becker, Bolton, Haehnelt, 2013, PRD, 88, 043502

  27. THE COSMIC WEB in WDM/LCDM scenarios z=0 z=2 z=5 Viel, Markovic, Baldi & Weller 2013

  28. THE WARM DARK MATTER CUTOFF IN THE MATTER DISTRIBUTION Linear cutoff for WDM 2 keV Linear cutoff is redshift independent Fit to the non-linear cut-off Viel, Markovic, Baldi & Weller 2013

  29. HISTORY OF WDM LYMAN-a BOUNDS Narayanan et al.00 : m > 0.75 keVNbodysims + 8 Keck spectra Marginalization over nuisance not done Viel et al. 05 : m > 0.55 keV (2s) Hydro sims + 30 UVES/VLT spectra Effective bias method of Croft et al.02 Seljak et al. 06 : m > 2.5 keV (2s) Hydro Particle Mesh method + SDSS grid of simulation for likelihood Viel et al. 06 : m > 2 keV (2s) Fully hydro+SDSS Not full grid of sims. but Taylor expans. Viel et al. 08 : m > 4.5 keV (2s) SDSS+HIRES (55 QSOs spectra) Full hydro sims (Taylor expansion of the flux) Boyarsky et al. 09 : m>2.2 keV (2s) SDSS (frequentist+bayesian analysis) emphasis on mixed ColdWarmDM models

  30. DARK MATTER DISTRIBUTION

  31. GAS DISTRIBUTION

  32. HI DISTRIBUTION

  33. “Warm Dark Matter as a solution to the small scale crisis: new constraints from high redshift Lyman-α forest data” MV+ arXiv:1306.2314 DATA: 25 high resolution QSO spectra at 4.48<zem<6.42 from MIKE and HIRES spectrographs. Becker+ 2011 SIMULATIONS: Gadget-III runs: 20 and 60 Mpc/h and (5123,7863,8963) Cosmology parameters: s8, ns, Wm, H0, mWDM Astrophysical parameters: zreio, UV fluctuations, T0, g, <F> Nuisance: resolution, S/N, metals METHOD: Monte Carlo Markov Chains likelihood estimator + very conservative assumptions for the continuum fitting and error bars on the data Parameter space: mWDM, T0, g, <F> explored fully Parameter space: : s8, ns, Wm, H0, UV explored with second order Taylor expansion of the flux power + second order

  34. THE HIGH REDSHIFT WDM CUTOFF dF = F/<F>-1

  35. RESULTS FOR WDM MASS EXCLUDED m > 3.3 keV (2s)

  36. SDSS + MIKE + HIRES CONSTRAINTS Joint likelihood analysis SDSS data from McDonald05,06 not BOSS

  37. M thermal WDM > 3.3 keV (2s C.L.)

  38. CONSTRAINTS FROM SDSS DATA ON COLD+WARM DM MODELS mthermal 2keV 1keV Boyarsky, Ruchayasky, Lesguorgues, Viel, 2009, JCAP, 05, 012

  39. CONCLUSIONS - NEUTRINOS Neutrino non-linearitiesmodelled in the matter power spectrum. correlation function, density distribution of haloes, peculiar velocities, redshift space distortions. NEW REGIME! Galaxy clustering data give <0.3 eV (2s upper limit). IGM still the most constraining probe <0.14-17 eV to be checked soon Forecasting for Euclid survey: 14 meV error is doable but need to model the power spectrum to higher precision (possibly subpercent) and with physical input on the scale dependence of the effect. Very conservative 20-30 meV

  40. CONCLUSIONS – WARM DARK MATTER High redshift Lyman-adisfavours thermal relic models with masses that are typically chosen to solve the small-scale crisis of LCDM Models with 1 keV are ruled out at 9s 2 keV are ruled out at 4s 2.5 keV are ruled out at 3s 3.3 keV are ruled out at 2s 1) free-streaming scale is 2x108M/h 2) at scales k=10 h/Mpc you cannot suppress more than 10% compared to LCDM Of course they remain viable candidate for the Dark Matter (especially sterile neutrinos) but in terms of structure formation nearly indistinguishable from CDM

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